<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>css的三种位置</title>
    <link rel="stylesheet" href="Demo.css">
    <style>
        p{
            color: blue;
        }
        h4{
            color: green;
            background-color: yellow;
        }


    </style>
</head>
<body>
    <div>我是div</div>
    <div id="tup">
        <div id="tu1"></div>
        <div id="tu2"></div>
    </div>
    <hr>
    <h4>我是标题</h4>
    <h4 style="color: red">我是标题</h4>
    <h4>我是标题</h4>
    <hr>
    <p>我是段落</p>
    <p>我是段落</p>
    <p>我是段落</p>

</body>
</html>